Your room where you listen, has a fair amount of impact on it. Chances are your room is altering the sound, and you over compensate. If the mixes sound decent in your room, but consistantly boomy in other listening environments, you need to lower the bass when mixing down. Foam de-coupling of speakers on stand for studio monitors is an issue. The shape of your room is very important. Low frequency sound waves, have much more powers, and can move around objects, they bounce off the walls, multiple times. Hi frequency sound waves get absorbed, and don't bounce around as much.
If speakers are too close to a wall, the wall also acts like a speaker effect. I had Mackie 825's for a while, and my mixes sounded great in my room, but pretty boomy in other situations. I had the money and bought a pair of Genelecs. Sound improved radically.
However you don't have to spend a fortune, on speakers. You have to 'fine-tune' your ears, to be more perceptive. So you can compensate in your mixes. Some engineers, will put a final bit of high end, on the output, or some bass roll-off, or even a notch in the mid-range. Listen to your instrument carefully. Often guitars, may have a moderate amount of low end, which sounds good, but when you add a bass, it starts to get muddy. I might roll off some bottom end, or notch on each of the guitar.
Being a recording engineer for decades of my life in professional studios, gives me an advantage in that department. In actuality, Yamaha has done an incredible job, of sound engineering. Their products consistantly give a better homogenous mix, (in part because of their EQ'ing, and use of limiter). Yes, sometimes, you might want to change or shut off the limiter, but in general, their settings are a good all around balance.
It's been quite a while since I used the Mackie speakers, if there is a low end roll off, try switching that in, Google some articles on sound mixing. you should find some helpful tips. re-positioning the speakers..A perfect rectangle room, is a hard place to mix, because of the sound bouncing around. I bought some foam squares, placed them in strategic places. The foam cylinders placed will weaken the power of bouncing low sound waves.
An old trick, is to keep lowering the master volume, and carefully listen to the mix. As you keep lowering notice what is left. If all you hear at the lowest settings is bass, drums, lower their volume. The best mix is a compromise. You want the mix to sound good on as many systems as possible. For years I worked at a nightclub. I would often have the DJ play my mixes in the beginning of the night, so I could compare them to other commercial releases. I freaked out at first, cause my mixes were so bass heavy. I compensated, by lowering the low end. So they did not sound their best, on my home system, but still passible. When played in the club. they sounded decent. I also began to notice, how many songs played in clubs, were not the best mixes. Often hip-hop music will have extremely loud drums, bass. Much more than suits my taste. But that is part of the style of hip-hop. Also those mixes sound better on boom-boxes and earbuds.
As a fine tuning of your ears, listen to as many commercial mixes as possible. Especially music thru the decades. Notice songs, where the snare drum is really too loud. The 80's music made a lot of use of loud 'gated' snare drums. But now, it just sounds so weird. Our ears have become conditioned to the current acceptable sounds.
Find music you really like, plug it into your system, and play your song, Although keys, tempos will clash listen to the balance of each instrument. Sometimes when working on a song, I get used to a certain, mix, balance, and then a few days later, I pull up the song, and think, '****, that kick drum is just way too loud. But I couldn't hear it before.
The performer will focus on their instrument, the guitar player will want his instrument to be the loudest, singer his voice etc.
When you mix-down. You have to stop being subjective, and become objective. You don't want to favor the instrument you play.
For instance, some musicians, a bit insecure about their abilities, (I'm not the best electric piano player), will subconsciously lower the electric piano. Mixing, mastering is an art form in itself. Like any talented person, they often spend most of their life, mastering their craft. It is forever a learning, listening, modifying process.
Hope this gives your some ideas to ponder.
Those of us here are usually playing all the parts, because of the nature of arranger instruments.
